Modeling And Calculation Method Analysis Of Hydraulic Units' Water Conveyance System Based On Two-port Network

Up till now,the calculation method of water hammer pressure can be divided into:graphical method,analytic method and numerical analysis method,numerical analysis method which is particularly widespread.The numerical analysis method which is according to the basic equations or the transformed equations and boundary conditions,solving the pressure time by time and pipe by pipe,the computing processes are complex;and the method had discretely solutions characteristics,unable to provide the continuous solutions of the pressure and can not be used to construct the continuous model of water conveyance system,while the stability theory and control strategy analysis for nonlinear systems are mostly based on state-space model,requirements in the study area is continuous and derivable,but numerical analysis method can't reach the purpose.Considering the various factors,research and analysis is focused on the modeling method,the solving method and the dynamic characteristics of the pressure water system,the research work and innovative results mainly include the following aspects:1.Use two-port network to describe the hydraulic units of the complex water conveyance system,and put forward “delay modeling method of water conveyance system based on e index”;the modeling approach is different from the way which using characteristic equation and boundary condition to determine the water system model,it also differs from that of only using simple pipe elastic or rigid model described the water system,its physical concept is more clear and the modeling is more convenient;2.On the basis of using two-port network to describe the pressure water conveyance system,proposed a “analytic method of water conveyance system delay model based on e index” to solve the water hammer pressure,the method can get the pressure analytic expression of the water system.At the same time, the hydraulic transition processsimulation experiment was carried out,and compared with the method of characteristics,to verify the validity and applicability;3.On the basis of “a delay model of water conveyance system based on e index”,then built the mathematical model of mathematical model,finally study the transient process and the law of the change of its parameters,also validated water conveyance system model and its solving method applicability and accuracy in the transition process of hydraulic unit.